LogP Performance Assessment of Fast Network Interfaces

			   David E. Culler
		      Computer Science Division
		  University of California, Berkeley

In recent years, we have seen dramatic advances in scalable,
low-latency interconnection networks for parallel machines and
workstation clusters.  With such "hot interconnects," the performance
of user-to-user communication is limited primarily by the network
interface, rather than the switches and links.  We present a
systematic performance assessment of the hardware and software that
provides the interface between applications and emerging high-speed
networks.  Using LogP as a conceptual framework and Active Messages as
the communication layer, we devise a set of communication
microbenchmarks. These generate a graphical signature from which we
extract the LogP performance parameters of latency, overhead, and
bandwidth. The method is illustrated on three diverse platforms: Intel
Paragon, Meiko CS-2, and a cluster of SparcStations with Myrinet. The
study provides a detailed breakdown of the differences in
communication performance among the platforms.  While the details of
our microbenchmark depend on Active Messages, the methodology can be
applied to conventional communication layers.